1. Field of the Invention
The present disclosure relates to thin film transistor (TFT) display technology, and more particularly to a pixel structure, an operation method, and an array substrate for enhancing a voltage regulation of the common electrode of a liquid crystal panel.
2. Discussion of the Related Art
Crosstalk is a common issue with respect to TFT-LCD displays, which means the image in a specific area may affect the image in another area. The crosstalk may include a vertical crosstalk and a horizontal crosstalk according to the location of the crosstalk. Taking the vertical alignment (VA) display mode as one example, the horizontal crosstalk means that the defective issue occurs along a horizontal direction. There are various reasons that may cause the crosstalk, here, only the horizontal crosstalk is discussed. Usually, different driving method may result in different horizontal crosstalk. For instance, the frame inversion may result in line-shaped horizontal crosstalk, and row inversion or column inversion may only cause slight horizontal crosstalk. However, regardless of the driving methods, the defective images are all caused by the capacitance coupling effect between the data line and the common electrode. When the potential of the data line changes, the parasitic capacitance (CDC) between the data line and the common electrode line (ACOM) forms an instantaneous potential jump in the common electrode line. IF the signal delay of the common electrode line (ACOM) is more serious or the voltage driving capability is not enough, the potential may not be back to a predetermined potential quickly. The potential jump may pull down a pixel spanning voltage by the coupling effect of the storage capacitance (Cst), which results in a lower brightness so as to form the horizontal crosstalk. With respect to the VA display mode, taking a row inversion as one example, the potential of the driving voltage of on data line is 128 grayscale, and another driving voltage has a two-thirds time of 128 gray-scale potentials, one-third time of 255 grayscale potential. The potentials of the two data lines are periodically inversed such that the potential of the common electrode lines changes accordingly, such change may result in a darker image. The horizontal area of the 255 grayscale potential may include a darker horizontal block due to a greater change of the common electrode line. Usually, the horizontal crosstalk may be solved by adopting the column inversion or the dot inversion. However, such solution may be easily affected by the change of the manufacturing process. That is, the left and the right data line may cause different capacitance coupling effect toward the common electrode line, and thus the horizontal crosstalk may not be eliminated at all.
Under 4MASK manufacturing process, the parasitic capacitance (CDC) between the data line and the common electrode line includes a first metal layer (Metal1), an AS layer, a SiNx layer, and a second metal layer (Metal2). The AS layer and the N+ layer are configured between the Metal1 and the Metal2, such that the parasitic capacitance (CDC) may be different in accordance with the positive frame or the negative driving method is adopted, which are respectively represented as CDC+ and CDC−. Such change may result in a greater difference between the capacitance coupling effect between the two data lines and the common electrode line.
Currently, the keel structure is transversely interpenetrated, and the metal lines at two sides provide DC driving voltage. Such design may cause the ACOM driving capability not enough. Thus, it is necessary to provide a structure and a method of high driving capability of the common electrode line (ACOM).